The association between BMI and body weight perception among children and adolescents in Jilin City, China.

We evaluated the association between BMI and body weight perception in a sample of children and adolescents.A cross-sectional school-based study was conducted among 7-18 year-olds (N = 9727) from 4 districts in Jilin City, China. We calculated BMI from measured weight and height and assessed body weight perception using a single questionnaire item. We analyzed these data using SPSS version 20.0.Approximately 19.8% of these youth perceived themselves as underweight, 57.8% as normal weight, and 22.4% as overweight. In reality, 4.9% were underweight, 64.3% were normal weight, and 30.8% were overweight. Furthermore, approximately 66.4% of these Chinese youth correctly perceived their body image, 28.2% underestimated their true body image, and 5.4% overestimated their weight status. Girls were more likely than boys to overestimate their weight (χ2 = 135.4, p < 0.05). Adolescents 13-18 years old were more likely than children 7-12 years old to overestimate their weight (χ2 = 248.4, p < 0.05). Senior high school students were the most likely to overestimate their weight (χ2 = 297.6, p < 0.05). Kappa tests revealed significant differences in consistency analysis of BMI and body weight perception (Kappa = 0.352, p < 0.05). Kappa < 0.4, the consistency of BMI and body weight perception was poor.A mismatch existed between BMI and body weight perception among these children and adolescents. Thus, schools and parents should take steps to help them improve weight management and overall health awareness.